1. Field of the Invention
The invention relates to a method for an automatic checking and quality determination of tablets or pills, where the tablets or pills are fed continuously from a tablet machine or pill pressing machine, as well as an apparatus for the automatic checking and quality control of tablets or pills.
2. Brief Description of the Background of the Invention Including Prior Art
Tablets, delivered from the tablet-pressing machine, are conventionally filled into drums in the tablet and pill production, where one charge for the drums represents one batch. Samples are taken at fixed and/or defined intervals from the tablet stream delivered by the tablet machine. These batch samplings are fed to a device for automatic quality control. The samples are subjected to various tests in this device such as, among others, a hardness test, a thickness measurement, a diameter determination, weighing, calibration. The results of these tests are compiled into reports and/or protocols. The batch samplings are removed from the tablet stream during the normal filling operation of the drums. The drums are automatically filled and thus the tablet stream can be directed from a full drum to an empty drum. Such modes of operations are known, among others, from the German Patent document DE 4,118,878-A1.
Since the withdrawal of the batch sampling occurs independently of the filling operation of the drums, and since the drums are continued to be filled during the removal of the batch samples, it has not been possible up to now to associate the protocols, prepared by the test device, with a specific drum. Until today it has only been possible to associate the protocols to an entire charge. Thus, if freak stray values are discovered within the protocols, which are not acceptable based on the preset quality specifications, then the entire charge has to be rejected, which can be associated with substantial expenditures.
A method for the quality assurance in the production of tablets has become known from the German Patent document DE-3,628,757-A1. According to this method, samples are withdrawn during the production of the tablets, where these samples are comprised of a plurality of tablets. The combined actual value of the weight of said plurality of tablets is compared to the set value of the weight. The tablet-compressing machine is then readjusted corresponding to the deviation between the actual value and the set value in order to bring the tablet weight to the set value. The weight of the individual tablets of the sampling are measured and compared with each other before a readjustment of the tablet machine. Upon determination that one or more tablets of the samplings deviate substantially in their weight from the set value, the statistics are rectified through a correcting calculation and the corrected value is employed for readjustment. The statistical evaluation of the measurement results as well as an automatic correcting calculation or a request for a second batch sampling occurs as determined with the aid of a computer. The data output of the computer is connected to a device for the readjustment of the filling charge weight or amount. This process is employed during the production of the tablets and does therefore not allow an association of the measurement results to a specific drum since, as stated above, the removal of a batch sampling occurs independent of the filling operation of the drums.